sys_core_fold: Remove uncovered clauses matching #c_map{}

sys_core_fold:eval_element/3 attempts to evaluate calls to element/2
at compile time or to warn when the call will obviously fail. For
example:

  element(1, [a])

will obviously fail and eval_element/3 will produce a warning.
eval_element/3 uses the helper functions is_not_integer/1 and
is_not_tuple/1 to test whether the arguments are known to be
incorrect. The clauses that attempt to match #c_map{} in those
helper function will never be executed, because #c_map{} will
never occur directly in an argument for a function call.

For example, code such as:

  element(1, #{a=>Val})

will be translated to:

  let <NewVar> = #{a=>Val}
    in element(1, NewVar)

since maps are not considered safe (some map operations may
cause an exception at run time).

1 files changed, 0 insertions, 2 deletions

diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl
index 09716d0866..f3e90f8eb2 100644
--- a/lib/compiler/src/sys_core_fold.erl
+++ b/lib/compiler/src/sys_core_fold.erl
@@ -1378,7 +1378,6 @@ eval_is_record(Call, _, _, _, _) -> Call.
 is_not_integer(#c_literal{val=Val}) when not is_integer(Val) -> true;
 is_not_integer(#c_tuple{}) -> true;
 is_not_integer(#c_cons{}) -> true;
-is_not_integer(#c_map{}) -> true;
 is_not_integer(_) -> false.
 
 %% is_not_tuple(Core) -> true | false.
@@ -1386,7 +1385,6 @@ is_not_integer(_) -> false.
 
 is_not_tuple(#c_literal{val=Val}) when not is_tuple(Val) -> true;
 is_not_tuple(#c_cons{}) -> true;
-is_not_tuple(#c_map{}) -> true;
 is_not_tuple(_) -> false.
 
 %% eval_setelement(Call, Pos, Tuple, NewVal) -> Core.